Comparing the Properties of GMCs in M33 from Simulations and Observations

Abstract

We compare the properties of clouds in simulated M33 galaxies to those observed in the real M33. We apply a friends of friends algorithm and CPROPS to identify clouds, as well as a pixel by pixel analysis. We obtain very good agreement between the number of clouds, and maximum mass of clouds. Both are lower than occurs for a Milky Way-type galaxy and thus are a function of the surface density, size and galactic potential of M33. We reproduce the observed dependence of molecular cloud properties on radius in the simulations, and find this is due to the variation in gas surface density with radius. The cloud spectra also show good agreement between the simulations and observations, but the exact slope and shape of the spectra depends on the algorithm used to find clouds, and the range of cloud masses included when fitting the slope. Properties such as cloud angular momentum, velocity dispersions and virial relation are also in good agreement between the simulations and observations, but do not necessarily distinguish between simulations of M33 and other galaxy simulations. Our results are not strongly dependent on the level of feedback used here (10 and 20%) although they suggest that 15% feedback efficiency may be optimal. Overall our results suggest that the molecular cloud properties are primarily dependent on the gas and mass surface density, and less dependent on the localised physics such as the details of stellar feedback, or the numerical code used.

15 pages, 12 figures, accepted by MNRAS

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Cited by in corpus (10)

• Giant Molecular Cloud Catalogues for PHANGS-ALMA: Methods and Initial Results
• Molecular Cloud Populations in the Context of Their Host Galaxy Environments: A Multiwavelength Perspective
• The role of galactic dynamics in shaping the physical properties of giant molecular clouds in Milky Way-like galaxies
• Evolution of giant molecular clouds across cosmic time
• How do different spiral arm models impact the ISM and GMC population?
• Spatial Power Spectra of Dust across the Local Group: No Constraint on Disc Scale Height
• Interstellar planetesimals: potential seeds for planet formation?
• Reconciling extragalactic star formation efficiencies with theory: insights from PHANGS
• Molecular cloud matching in CO and dust in M33 II. Physical properties of giant molecular clouds
• Stellar Feedback Effects on the Mass Distribution of Clouds and Cloud Complexes